Boiler



Nov. 3, 1931. w. H. ARMACOST BOILER.

Filed April 17. 1928- 3 Sheets-Sheet 1 Nov. 3, 1931; w. H. ARMACOSTBOILER ril 17 M 2 TM N K 8 N T k, A a? r m M 3 W Q a 2 9 1 Filed Nov. 3,1931.

w, H. ARMACOST v BOILER Filed April 17. 1928 5 Sheets-Sheet 3 INVENTOR.I

Myfiur A'rmacauf' A TTORNE Y.

Patented Nov. 3, 1931 UNITED STATES PATENT OFFICE wrrmm n. annmcosr, orNEW roman. Y., ASSIGZN'OR TO THE surnnnmrnn com PANY, orNEw YORK, N. Y.

BOILER Application filed April 17, 1928. Serial No. 270,664.

j This invention relates to water-tube boilers equipped with steamsuperheaters.

-It is correct theoretically, and has been found expedient in practice,to locate the steam superheater in a position such that the gases fromthe furnace come into contact with the superheating surface after theyhave passed over sufiicient boiler surface to remove enough of the heatso that the superheater will not be endangered, but to keep thesuperheater as close to the furnace as is consistent with thisprotective idea. In ortages mentioned above.

dina'ry boiler operation the output of the boiler will be variable butthe location just described results in a substantially constant finaltemperature of the steam leaving the 'superheater even under great loadvariations. Superheaters placed at a point more remote from the ,furnacedo not obtain such temperature uniformity. a

In boilers of the so-called horizontal watertube type, it has becomequite customary to locate the superheater in what is called theinterdeck position to obtain the advan- The boiler is, in other words,subdivided into two banks, a lower and an upper, the superheater beinglocated between them. The lower bank is made relatively small in size,consisting of three to five rows of tubes which are exposed-to thefurnace gases and'furnace radiation throughout their entire length. Theupper bank is usually b'aflied to give three passes to the gases. Thesuperheater is placed in the first of these passes in the free spacebetween the two banks, or it is distributed throughout the free spacebetween the two banks from ,front to rear of the boiler. I

This generalarrangement is good except for the fact that it results in aconsiderable amount of waste space within the boiler,

I making the setting for the entire boiler unnecessarily large andexpensive. Other types of boilers, such as the Sterling type, are even"more objectionable on this score.

'It is the object of the present invention -to provide a boiler with anideal space for longitudinal vertical section through a boiler of mydesign, Fig. 2 is a similar view of a somewhat modified form of theinvention, and Fig. 3 is a similar view of a further modification.

Referring first to the form illustrated in Fig. 1, the furnace is shownat 1, the boiler proper being located above the furnace. The walls ofthe furnace 1 are surrounded on all sides by water screens. At thefront, for example, the water tubes 2 and 3 connected to lower and upperheaders 4 and 5 screen the wall 6 against the intense radiant heat ofthe furnace. Rear wall 7 is similarly screened by water tubes 8andconnected to lower and uplimited in thisrespect, and a furnace usingsolid fuel and equipped for this purpose with the proper grate may besubstituted.

The boiler proper is enclosed in the housing 13. Against the front andrear walls ofthis houslng are arranged the headers 14 and '15 which arepreferably sectional but may be of the so-called box header type ifdesired. A bank of tubes 16 extending at the usual angle from front toback and comprisingthe proper number of rows of tubes connects these twoheaders. The'exact number of rows may vary from case to case, dependingupon circumstances. While the bank is somewhat inclined to thehorizontal, the usual practice of calling it a horizontal bank will befollowed hereinafter.

Located about centrally above the bank 16 and at some distance above itis the drum 17. This is connected to the upper portion of headers 15 bythe bank of tubes 18. The lower portions 19 of these tubes are straight,and parallel to the tubes 16 and are connected by bends to the verticalstraight portions 20. The upper ends are bent toward and connected tothe drum 17.

Front headers 14 extend vertically some distance above the bank of tubes16 and their upper ends are connected to drum 17 by the circulators 21.The tubes making up the water screen 3 have their upperends connected tothe lower ends of the headers 14.

The upper header 10 of the water screen 8 is connected at one or bothends by means of the riser or risers 22 and the pipes 23 to the drum 17.These risers 22 and pipes 23 preferably lie laterally entirely outsideof the outline of the boiler, the drum 17 being extended beyond thesetting at one or both ends, as required.

On the top of the bank of tubes 16 a horizontal baffle 24 extends fromthe rear headers 15 forward, stopping at the point 25 some distance fromthe front headers, from which point a vertical baflle 26 extends upwardadjacent to the front of the tubes 18.

A vertical baffle 27 between baffle 26 and the rear wall of the housingextends from a point some distance above the baflie 24 upward. A shortbaflle 28 closes the space between this baffle and the drum 17.

The entire space between the front headers 14 and the baflle 26 isoccupied by the superheater 29. This superheater comprises verticallyarranged tubular loops connected to the two headers 30 and 31 lyingoutside of the setting of which 31 is connected by pipe 32 to the steamdrum 17 and of which 30 delivers the superheated steam to the steam main(not shown). The straight portions of the tubular units connecting thelooped structures to the headers extend through between the circulators21. In the upper portion of the last pass is located the economizer 33.

Between the lowermost of the tubes 18 and the baffle 24 there is leftjust suflicient space for a soot pocket.

At the lower ends of the rear headers 15 is the sludge chamber 34connected to the lower ends of the headers 15 by the connectors 35.Sludge is periodically blown off from this chamber in the usual manner.

The lower rear headers 9 are connected to the steam drum 17 at one orboth sides by the downcomer or downcomers 36.

The form of the invention shown in Fig. 2 is substantially like that ofFig. 1. the prin cipal difference residing in the battling of the curvedbank of tubes. The rear bank of tubes is divided into two portionsseparated by a space 37;. and the baffle 27 insteadof crossing the tubeslies entirely on the uppermost row of tubes 38 of the first portion ofthe bank. Convenient access is thus furnished for the maintenance ofthis baflle. A man can enter through the hole 39 and inspect and repairthe baffle. Preferably two additional rows of tiles 40-4O extend fromthe baffle 27 to the rear bank in order to direct the gases out of thespace 37 into the rear portion of the bank.

The baffle 26 is in this form shown as lying between the verticalportions of the two first rows of tubes of the upper bank;

In the form of the invention according to Fig. 3, the rear header 15does not extend up far enough to have thelower ends of the upper bank 18secured to it. Instead, a lower drum 41 is used, parallel to the upperdrum 17 and adjacent to the header 15, to which it is connected bynipples 42. The tubes of the bank 18 are given the more conventionalshape in this case of tubes extending between drums, although this isnot essential. With the shape shown for these tubes the superheaterspace becomes more nearly triangular, and it will be found moreconvenient to give the superheater elements 29a the shape shown in thedrawing and to have the headers 30a and 31a in front of the front wallof the setting. I

It will beseen' that the boiler provided by my invention hassubstantially every available cubic foot within the setting occupied byheat absorbing surfaces. By having the upper bank of tubes extendforward and upward and locating the drum 17 at a considerable heightabove the lowest point of the boiler, the difference in hydrostatic headof the portions of the boiler containing the heated water mixed withsteam and the portion containing the water flowing downward from thedrum is emphasized and the circulation within the boiler greatlypromoted.

I claim:

1. In apparatus of the class described, the combination of verticalfront and rear headers, a bank of horizontal water tubes connectingthem, a transverse steam and water drum some distance above the bank andap proximately midway between the headers, a

' second bank of water tubes connected to one" of the headers andextending toward the other header to a point under the drum and thenupward toward the drum, a connection from the second header to the drum,asuperheater in the angular space formed by the two banks, a housingenclosing the boiler and superheater, and a connection from the saidsecond bank comprisin straight lengths parallel to the first bank anvertical straight lengths, a bafiie comprising a portion extending abovethe first bank from the rear header to a point short of the front headerand a vertical portion along the second bank and terminating short ofthe drum, a superheater abovethe first bank and forward of the verticalportion of the baflie, a housing enclosing the boiler and superheater, aconnection from the front header to the drum, and a ifconnection fromthe drum to the superheater. 7

3. In apparatus of the class described, the combination of a boilerhousing, a bank of substantially horizontal, straight water tubesextending from front to' back of the housing, a bank of curved watertubes above the first named bank distributed through the space from therear wall to a point spaced from the front wall, said curved tubeshaving portions generallyparallel to the first bank, and generallyvertical portions, and a superheater comprising tubular elementsdistributed through the space between said point and the front wall, asteamand water drumto which one end of all the tubes and the superheaterare connected, and means interconneoting all the water tubes at theirother ends. v

4. In apparatus of the class described, the combination of a boilerhousing, a bank of substantially horizontal, straight water tubes-extending from front to back of the housing,

3 a bank of curved water tubes above the first named bank distributedthrough the space from the rear Wall to a point spaced from the frontwall, said curved water tubes having portions generally parallel to thefirst 40 bank and generally vertical portions, said horizontal portionsof the lowermost of the curved tubes being spaced only a small distancefrom thehorizontal bank, and a superheater comprising tubular elementsdistributed through the space between saidpoint and the front wall,whereby the entire space between the front and back of the housing isoccupied by heat absorbing surfaces, a steam and water drum to which oneend of all the water tubes and the superheater are connected, and meansinterconnecting all the water tubes at their other ends.

5. In apparatus of the class described, the

ends of all the tubes communicate, and a superheater distributeduniformly through the remaining portion of the space above thehorizontal bank, said superheater being connected to said drum.

- 6. In apparatus of the class described, the combination of a boilerhousing having front, rear, and side walls, a baffle extending from therear wall forward to a point spaced from the front wall, a baffleextending upward from this point, a bank of substantlally horizontalwater tubes below the horizontal baflle and extending from front to rearof the'housing, other water tubes arranged within the angle formedby-the two baffles and extending from the rear wall forward and upward,header means interconnecting the rear ends of allthe tubes, a steam andwater drum with which the other ends of all of the tubes communicate,and a superheater arranged in the space between the upwardly extendingbafiie and the front wall, said superheater being connected to saiddrum.

7. In apparatus of the class described, the combination of a boilerhousing having front, rear and side walls, a steam and water drum at thetop of the housing, water containing means adjacent to the rear wallbelow the drum, water tubes connecting the water containing means andthe drum, said tubes being distributed throughout the space from side toside and from the back to a point spaced from the front wall, whereby aspace is left extending from side to side and from the front to saidpoint, header means adjacent to the front wall and above said watercontaining mean-s, a bank of water tubes connecting said header meansand, said water containing means and distributed from side to side,connections to the drum from said header means, and a superheaterdistributed throughout said space above said bank of water tubes andconnected to the header.

WILBUR H. ARMACOST.

to a point intermediate between the front and rear walls, headermeans'interconnecting the ends of the horizontal portions of'the curvedbank and one set of ends of the horizontal bank of tubes, a drum withwhich the other

